High temperature lead assembly



May 2, 1961 s. E. GREGOIRE ETAL 2,982,937

HIGH TEMPERATURE LEAD ASSEMBLY Filed Oct. l, 1957 a' l Z4 gama/JW yUnited tates Patent @nice 2,982,937 Patented May 2, 1961 HIGH TEMPERATURE LEAD ASSEMBLY Stephen E. Gregoire and Richard J. Davies, Sidney, and Samuel A. Schroeder, Bainbridge, N.Y.,` assignors to The Bendix Corporation, a corporation of Delaware Filed Oct. 1, 1957, Ser. No. 687,417

4`Claims. (Cl. 339-89) This invention relates to electrical apparatus and more particularly to means for effecting terminal connections between electrical conductors.

vOne of the objects of the present invention is to provide a novelly constructed electrical terminal which will provide a satisfactory electrical connection throughout a wide range of temperatures and at substantially high temperatures.

Another object of the invention is to provide novel cooperating male and female electrical terminals for efecting a connection between conductors in hermetically sealed units.

Another object is to provide electrical terminal means wherein parts having diiferent coeicients of expansion are novelly constructed and assembled to compensate for expansion and contraction of such parts resulting from temperature variations extending from below 65 F. to l000 F. and more.

The above 'and further objects and novel features of the present invention will more fully appear from the following detail description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a denition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

Fig. 1 is an elevation view, mostly in section and with parts broken away, showing one form of electrical connector means embodying the present invention; and

Fig. 2 is a detail elevation view of ya part of said terminal.

'I'he single embodiment of the invention illustrated in the accompanying drawings, by way of example, is in the form of separable or detachable connector means adapted for making an electrical connection between electrical conductors in hermetically sealed containers or conduits. The novel construction shown is designed to withstand the high temperatures encountered in use on jet type engines, missiles and the like and to hermetically seal an insulated conductor in a flexible shielding conduit for protection against electrical flashovers at low` atmospheric pressures occurring at high altitudes.

In the form illustrated, the socket contact assembly of the novel structure contemplatedby the invention comprises a tubular metallic shell 10 hermetically secured in an opening of a casing 11. The shell and casing may be integral if desired. A tube or sleeve 12 of heat reshoulder in shell 10. Within cylindrical portion 15, insulating tube 12 is provided with a metallic surface coating to which said cylindrical portion is circumferentially brazed by means of a tine silver or nickel braze. The central cone-like portion 16 and the inner unsecured portion of flange 17 function as a ilexible diaphragm which absorbs or compensates for differences in the expansion and contraction of the various assembled parts when the same are subjected to wide Variations of temperature. An hermetic seal is also formed by member 14 between insulator 12 and shell 10.

A novel socket contact assembly is provided Within and hermetically seals the bore through insulating tube 12. Said assembly comprises an inverted cup-like metallic member 18 having a cylindrical portion 19 and an internal flange 20 connected by a cone-like portion 21. Cylindrical portion 19 is circumferentially brazed to a metallic coating on the inner surface of the end portion of insulating tube 12. A cup-like socket contact 22 has a clearance tit in the bore of insulator 12 and engages the closed end of member 18. The `adjacent ends of cup members 18 and 22 are preferably provided with matching holes for receiving a rigid pin 23 which may function as a rivet mechanically connecting said members and4 as a connector for a conductor within casing 11. The parts may be silver soldered or brazed together around thepin-receiving hole to complete the hermetic sealing of the bore of insulator 12. Member 18 functions as a diaphragm while member 22 is slidable in tube 12 to compensate for relative movement of the parts caused; by expansion and contraction caused by the heating and cooling of the parts in operation. Cup member 22 is advantageously made of nickel or is nickel plated to prevent its becoming oxidized during use.

The plug or male terminal of the connector is likewise novelly constructed to function with complete satisfaction at high as well as low temperatures and to provide an hermetic end seal for a conductor conduit. As shown, the lead assembly embodying the plug terminal comprises a conductor 24 covered with electrical insulation 25 which will withstand high temperatures. In one suitable embodiment, conductor 24 was wrapped with tape consisting of ceramic iibers in sheet form laminated with glass cloth and covered with one or more braided layers of yarn made of silica fibers. The insulated conductor may be covered by a tube 26 of woven metallic strands. Surrounding the shielded cable above described, is a flexible, impervious conduit :comprising a corrugated metal tube 27 covered by a braided metal tube 28. The ends of tubes 27 and 28 are connected together, such as. by heliarc welding, in a welded assembly with a ring 29 and a metal sleeve 30 to form an hermetically sealed joint. The braided cover 26 of the cable is cut oft` short of the end of insulated conductor 24, 25 and is circumferentially fanned out at 31 to lie between ring 29 andv the end of a metal tube 32. The vengaging parts are welded, as by heliarc welding, to form an hermetically sealed joint.

The insulated conductor 24, 25 extends into a ceramicy tube 33 which is novelly suspended or supported within and in radially spaced relation to metal tube 32 by a metal diaphragm 34. The latter may consist of two cylindrical portions 35 and 36, one of which fits into and is circumferentially brazed to metal tube 32, and the other of which surrounds and is brazed to an external metallic coating on the end portion of ceramic tube 33. The cylindrical portions 35, 36 are integrally joined by a conical portion 37 which provides for any necessary relative movement or expansion between the connected parts when the same are subjected to temperature variations.

The lower or outer end portion of insulating sleeve 33, as viewed in the drawing, is of reduced diameter for passing an uninsulated end portion of conductor 24. Surrounding said reduced end portion and brazed to a metallic coating thereon in `a hermetic manneris a tubular metallic tip or nose pieceV 38, the end of which pref-V erably extends beyond ceramic tube 33. Conductor 24 extends beyond the tip piece and through'a central opening'in the bottom of a cup-shaped male contact terminal 39, and the three are heliarc or otheiwise suitably welded to form `an hermetic seal at the end of the bore through tip piece 38. A Y Y Y Contact member 39 has `the side wallsl thereof slotted to form a plurality of resilient ingers 46 (Fig. 2) and is adapted to slidablyiit into socket contact 22 for electrical contact therewith. For the purpose of assuring firm and good electrical contact between ingers 49 and socket 22 Vunder high heat conditions, contact terminal 39 may be ofpbi-metal construction and of such a nature that fingers 40 will bend or push outwardly when subjectedV to heat. Preferably, however, contact rnernbery 39 is fabricated from soft annealed nickel or the like and a split annular bi-metallic member 41 capable of withstanding extremely high temperatures is provided within terminal member 39 and held against axial displacement by an annular groove 42 in tip piece 38. Member 41 exerts some expansive force upon member 39 at room temperature to assure good contact between members 39 and 22. When subjected to high temperatures, the bi-metallic member 41 expands to maintain lingers 40 in rm and good electrical contact with socket contact 22.

The connector parts may be positively held in assembled position by detachable means, as shown. A flanged nut 44 ts over and contacts the edge of a ange 45 on housing member 32. The nut has threaded engagement Y at 46 with the confronting end of housing 10, thereby to draw and maintain the two housings together. If desired, the two housings may be sealed to each other by an annular sealing ring 49 which is carried in a seat on the end of housing and is compressed between the ends of the housings. Housing 32 may be extended, if desired, in a circular cylindrical portion 47 which lies between housing 10 and tubular insulator 12. Portion 47 'aids in the preliminary aligning of the connector parts upon their assembly, and also functions to guard the parts of the male or pin connector against injury when'it is'disconnected and withdrawn from socket 22 and housing 10.

Although only a limited number of embodiments of the `invention have been illustrated in the accompanyingy drawings and described in the foregoing specication, it is to be expressly understood that various changes, such as in the relative dimensions in the parts, materials used, and the likeas well as the suggested manner of use o-f theapparatus of the invention, may be made therein Vwithout departing from the spirit andY scope of the ingated metal shell, a gas impermeable electrically 1nsulating ceramic tube mounted generally coaxially within the shell, a yieldable annular metal gas impermeable diaphragm interposed between and sealingly connected to the tube and shell for supporting the tube in the shell,

relationship.

2. A separable electrical connector as defined in claim 1, wherein each of the annular diaphragms has an inner and an outer terminal ilange, said anges being sealed, respectively, to the tube and the shell, each diaphragm having a exible generally transversely 'extending portion between the shell and the tube.

3. A separable electrical connector as defined in claim 2,V wherein the rst tube, of a iirst connector part, mounts a socket contact, said first tube is of larger diameter than the other, second tube of the second connector part, said second tube mounts a pin-type contact on its inner end confronting the irst connector part, the socket contact is mounted intermediate the ends of the first tube, and the second tube is telescopically received within the first tube when the pin and pin-type contact and socket contact are in engagement.

4. A separable electrical connector as deiined in claim 3, wherein the first shell is appreciably spaced radially of the first tube, wherein the second shell is appreciably spaced radially from the second tube, and wherein the parts are so constructed and arranged that, when the connector parts are in mating confronting engagement, the inner end of the second shell is telescopically Vreceived within the space between the first shell and the iiist tube, andthe inner end of the first tube is telescopically received within the space lbetween the second shell and the second tube. Y

References Cited in the tile of this patent UNrrED srArns PATENTS 1,635,830 Gagnon July 12, 1927 1,797,581 Kuhn et al. Mar. 24, 1931 2,194,886 Dallenbach Mar. 26, 1940 2,200,694 .Gerecke et al. May 14, 1940 2,230,277V Volker et al Feb. 4, 1941 L 2,318,435 Stupakol et al May 4, 1943 2,440,279 Larkins Apr. 27, 1948 V2,642,474 Bowar June 16, 1953 2,695,390 Woolstonet al Nov. 23, 1954 2,698,367 Poitras Dec. 28, 1954 2,740,098 Phillips Mar. 27,V 1956 V2,759,989 Anderson" Aug. 21, 1956 FOREIGN PATENTS 140,318 Great Britain Mar. 25, 1920 307,059 'Germany Oct. 17, 1919 538,757 YGreatBritain Aug. 15, 1941 *826,320 27, 1951 'Germany Dec. 

